Twenty-four-year-old newspaperman Ray Sargent is a hardened cynic in the ways of the world: he's lost his parents and brothers, served in the Marines in France, survived the deadly flu pandemic of 1918, and written up everything from labor strikes to gambling dens. And he has a way with women—or so he supposes. But he's never met a woman like Marian Newhouse, the beautiful, brilliant reporter with a mysterious past who shows up in Toledo, Ohio, just as the Midwest's "glass city" is getting ready to host the biggest sports event in the world—a heavyweight championship fight between Jack Dempsey and Jess Willard.

It's a time when everything seems up for grabs in the United States, when a midsize manufacturing city becomes the locus of national attention, and when a man who thought he had life figured out finds himself surprised by the oldest surprise of all.

As a suffocating heat wave descends and Toledo's streets fill with out-of-town visitors, Ray befriends both boxers. On July 4, with the sun beating down on thousands in an open-air arena, a bell rings to settle the issue between Dempsey and Willard—but can Ray win Marian's heart before she marries a man she barely knows?